Benzanthrone derivatives and process of producing the same



Patented June 19, 1928.

UNITED STATES PATENT orrlca;

KARL ZAHN AND WILHELH ECKERT, F HOGHST-ON-THE-MAI'LN, GERMANY, ASSIGNORS TO GBASSELLI DYESTUFF CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE.

BENZANTHBONE DERIVATIVES AND PROCESS OI PRODUCING THE SAME.

No Drawing. Application filed Kay 27, 1828, Serial No. 112,130, and in Germany June 27, 1925.

Our present invention relates to new benzanthrone derivatives. i We have found that valuable derivatives of benzanthrone are obtained by treating nitrobenzanthrones with an alkali metal sulfite. The new compounds thus obtained are soluble in water and probabl contitute sulfonic acids of aminobenzanthrones, the preparation of which in any other way has not been described hitherto. They are already dyestufis perse and give brilliant red dyein s for instance'on' wool, silk and acetate si they are, however, also particularly useful as parent material for the production of other-dyestufis. The followin example serves to illustrate our invention, ut is not intended to limit it thereto:

100 parts of nitrobenzanthrone, as it is obtained according to Example 1 of patent of addition No. 6,435 to French Patent No. 349,531 are brought into a finely subdivided form, preferably into the form of a paste, and then boiled on the reflux cooler with 1000 rts of a technical solution of sodium bisul to until the whole or nearly the whole mass has undergone reaction. After having diluted the mass with hot water the unattacked arent material is isolated by filtration. he resulting solution is then acidified, the sulfurous acid is expelled by boiling for a short time and the reaction product is se arated by the addition of common salt. en dry, it forms a dark red powder which ,readily dissolves in hot water to a red solution. Its solution in concentrated sulfuric acid is of a brownish yellow color with a black fluorescence. It dye; wool in an acid bath bright red tints.

We claim:

1. Benzanthrone derivatives substantially identical with the products obtainable by treatin a nitrobenzanthrone with an alkali metal hisulfite, being red powders, soluble in hot water with a red color, in concentrated sulfuric acid with a fluorescent brownish yellow color, dyeing wool from an acid solution brilliant red tints.

2. Benzanthrone-B'z 1 amino 2-sulfonic acid of the following formula:

SOIH

In testimony whereof, we afiix our signatures.

KARL ZAHN. WILHELM ECKERT. 

